<!DOCTYPE html>
<html>
  <head>
    <title>drawFocusIfNeeded()</title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <link rel="author" title="W3C">
    <link rel="help" href="http://www.w3.org/TR/2dcontext/#dom-context-2d-drawFocusIfNeeded">
  </head>
  <body>
    <h1>Description</h1>
    <p>This test uses drawFocusIfNeeded to draw a complex path focus then compare ImageData from before and after.</p>
    <div>
      <p>Before:</p>
      <canvas height=100 width=100 id='original'>
      </canvas>
      <p>After:</p>
      <canvas height=100 width=100 id=canvas>
        <p id='element' tabindex='1'>This is text.</p>
      </canvas>
    </div>
    <script>
    test(function() {
          var canvas = document.getElementById('canvas');
          var context = canvas.getContext('2d');
          var element = document.getElementById('element');
          element.focus();
          context.fillStyle = 'white';
          context.fillRect(0, 0, 100, 100);
          context.beginPath();
          context.strokeStyle = 'black';

          context.moveTo(10, 40);
          context.lineTo(50, 10);
          context.lineTo(90, 40);
          context.lineTo(70, 40);
          context.lineTo(70, 90);
          context.lineTo(30, 90);
          context.lineTo(30, 40);
          context.closePath();

          context.stroke();
          context.save();
          var refImage = context.getImageData(0, 0, 100, 100);

          assert_equals(40000, refImage.data.length, "ImageData.data.length is 40000");

          var original = document.getElementById('original');
          var o_context = original.getContext('2d');
          o_context.fillStyle = 'white';
          o_context.fillRect(0, 0, 100, 100);
          o_context.putImageData(refImage, 0, 0, 0, 0, 100, 100);



          context.beginPath();
          context.moveTo(5, 40);
          context.lineTo(50, 5);
          context.lineTo(95, 40);
          context.lineTo(95, 45);
          context.lineTo(75, 45);
          context.lineTo(75, 95);
          context.lineTo(25, 95);
          context.lineTo(25, 45);
          context.lineTo(5, 45);
          context.closePath();

          context.drawFocusIfNeeded(element);

          var ringImage = context.getImageData(0, 0, 100, 100);
          assert_equals(40000, ringImage.data.length, "ImageData.data.length is 40000");

          // make sure refImage and ringImage are different
          var length = 40000;
          var index = length;
          var identical = true;
          while (--index > 0) {
            if (refImage.data[index] != ringImage.data[index]) identical = false;
          }

          assert_false(identical, "A focus ring appears in the canvas");


      }, 'drawFocusIfNeeded does draw a focus ring if the element is in focus and the user activated a particular focus ring.');
    </script>
    <div id="log"></div>
  </body>
</html>
